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First Exam PHSX L1.L, Spring 2005

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

L) Science is a body of knowledge that

A) is an ongoing activity of humans.

B) condenses knowledge into testable laws.

C) describes order in nature.

ffimr of the above choices are correct.\J

E) None of the above droices are correct.

2) Whidl of the following is a scientific hypothesis, according to the text's working definition?

A) There are parts of the Universe we will never know about.-rr\

( B)tthere is no life on Mars.

C) There are things we will never know about.

D) Matter is filled with undetectable particles.

E) None of the above.

3) What item or items were stolen in a fratemity house Feynman was in?

A) Beer keg

B) Group pictures of the fraternity

C) All slide rules,-\,( D))A, door

E) English literature texts

4) A scientific statement that can never be changed is a scientific

A) law.

B) theory.

C) principle.

D) hvpothesis.. 4 , "(E) None of the above choices are correct.

5) As-an obiect freely falls downward near the Earth, its. , 4

(3)iPneea increases

B) acceleration increases.

C) inertia decreases

D) all of the above

E) none of the above

6) Whirl a rock at the end of a string on a frictionless ice-covered pond and it follows a circular path. If the stringbreaks, the tendency of the rock is to

A) stop moving

B) continue to follow a circular path.

( CDfollow a straight line path

D) all of the above

E) none of the above

7) The gain in speed each second for a freely-falling (no air resistance) object is about

A) 0.^\p)10 m/s,C) 20 m/s.

D) 5 m/s .

E) depends on the initial speed

8) A truck is moving at constant velocity. Inside the storage compartrnent, a rock is dropped from the midpoint ofthe ceiling and strikes the floor below. The rock hits the floor

A) behind the midpoint of the ceiling.

Aahead of the midpoint of the ceiling.

(!)xactly below the midpoint of the ceiling.

D) More information is needed to solve this problem.

E) none of these

9) A moving body must undergo a change in

A) direction. B) distance. C) velocity. D) acceleration

10) When a rocket ship accelerating in outer space runs out of fuel it

A) accelerates for a short time, slows down, and eventually stops.

B) stops suddenly.^\( C) ho longer accelerates.\-/D) accelerates for a short time, then slows down to a constant velocity.

E) continues to accelerate until something stops it

@o,itio,,.

11) Which of the following is not a vector quantity?

A) acceleration

@)sp"ea\d velocity

D) displacement

E) all are vector quantities

L2) A qar maintains a constant velocity of L00 km/hr for 10 seconds, During this interval its acceleration is

/-A1r"ro. B) 1000 km/hr. C) 110 km/hr. D) 10 km/hr-s E) 10 km/hr.

13) The muzzlevelocity of a bullet fired from a new rifle is 100 m/s. Neglecting air resistance, at the end of onesecond a bullet fired straight up into the air will lave traveled a distance of

A) 105 m. B) 100 m. fEt *, D) 5 m. E) none of these\J

L4) A man leans over the edge of a cliff and throws a rock upward at 5 m/s. Neglecting air resistance, two secondslater the rock's speed is

A) zero'

B ) 5 m / s .

(C)/s m/s.

D) 10 m/s.

E) none of the above.

L5) One half second after starting from rest, a freely-falling object will have \fpeed

of about

A) 20 m/s. B) 10 m/s. C) 2.5 m/s. Qp

m/s. E) none of these

L5) if one object has twice as much mass as another object, it also has twice as much

A) velocitv.,,4.f B)./nertia.

C) acceleration due to gravity.

D) volume.

E) all of these

17) A 10-N falling object encounters 4 N of air resi{ce. The net force on the object is

A ) 4 N . B ) o N . ( 9 b N . D ) 1 0 N .

^\( C)10 m/s D) 15 m/s E) 5 m/s

@'

E ) 1 4 N

18) The maximum acceleration of a car while towing a second car twice its mass, compared to its acceleration withno car in tow, is

/Dpne third. B) one half. C) one fourth. D) the same. E) none of these

19) An object falls freely from rest on a planet where the acceleration due to gravity is twice as much as it is onEarth. In the fust 5 seconds it falls a distance of

A) 500 m. B) 150 m. C) 100 m.@to

r". E) none of these

20) Disregarding air drag, how fast must you toss a ball straight up in order for it to take 2 seconds to return to theIevel from which you tossed it?

A) 7.5 m/s B) 20 m/s

2L) Ten seconds after starting from rest, a car is moving at 40 m / s. What is the car's acceleration in meters persecond per second?

A) 400 c) 0.2s D) 40 E) 10

22) A 1000-kg automobile enters a freeway on-ramp at 30 m/s and accelerates uniformly up to 50 m/s in a time of10 aeconds. How far does the automobile travel during that time?.a\

/ e ) 4 o o m B ) 2 0 0 m C ) 1 0 0 m D ) 3 0 0 m E ) 5 0 0 m

23) A L0-kilogram block with an initial velocity of 10 m/s slides 10 meters across a horizontal surface and comes torest. It takes the block 2

fqnds to stop. The stopping force acting on the block is about

A) 10 N. (9t0 *. c) s N. D) 2s N.

24) BEGINNiNG HERE ARE THE EXTRA CREDIT QUESTIONS

9'*

An astronaut on another planet drops a L-kg rock from rest and finds that it falls a vertical distance of 2.5meters in one second. On this plane! the rock has a weight of

A ) 1 N . B ) 2 N . c ) 3 N . D ) 4 N . @*'25) Frank Wilczek used which of these as an analogy for the most fundamental nature of matter and energy as we

know it today?

A) Trees in a forest

B) Pointlike particles

C) A miniature solar system.

P) Bricks in a building/^\

1E)Musical Vibrations\-/

26) Vvhich of the following was NOT a part of either of the replicas of medieval weapon the Trebouchet constructedfor the NOVA special?

A) lead counterweights,r^.

[B) ]igttt for aiming

C) a wooden axle allowing the arms to swing

D) wheels on the bottom

E) a counterweight made of a wooden bucket filled with dirt or rocks

27) Anobject starts at rest and moves with acceleration which INCREASES at 2 meters per second per second,every second. How far has it moved after 5 seconds?

E) none of these

E ) 1 2 mB) 18m C ) 1 0 8 m D ) 3 5 m

28) Chris Mooney described whidr is these as the main problem with science journalism?

A) Not enough attention to medical research

f'B)Eoncentration on fringe views in an effort to provide "balance"\ ,tsf No views presented other than those of mainstream scientists

D) Too much emphasis on space missions

E) Not enough access to top secret researdr